It has long been known that the Sasa extract shows an anti-microbial activity. For instance, there have been reported anti-microbial effects thereof on Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli which are causative bacteria of wound-infectious diseases as well as anti-microbial effects thereof on Helicobacter pylori as the causative bacteria of gastric ulcers.
Sporangial and asporogenic anaerobes serving as causative bacteria of tetanus, gas gangrene and a variety of purulent infectious diseases cannot be disregarded as causative bacteria of wound-infectious diseases, but there has not yet been conducted any investigation of the anti-microbial activities for these anaerobes.
In the evaluation of substances having anti-microbial actions, it would be quite important to recognize the effects of such substances on useful and opportunistic bacteria which are settling in the skin and mucosae as parasitic bacteria, in addition to the effects thereof on the human pathogenic bacteria.
Incidentally, Lactobacllus spp. has been known as a parasitic bacterium settling in the oral cavity, digestive tract and vagina. In this respect, it has been well-known that the parasitic bacteria have two-sided actions on the living body. The Lactobacllus spp. is likewise sometimes isolated from clinical materials including blood and therefore, the effect thereof on the living body from the pathogenic aspect must not be underestimated. However, the frequency of the same isolated from such materials is quite low and therefore, it has been considered as a highly useful bacterial species in each particular anatomical site. For this reason, it is quite interesting to recognize or evaluate the magnitude of the anti-microbial effect of a Sasa extract on the Lactobacllus spp. which has been considered to be a bacterial group highly useful for the human being, but there has not yet been reported any detailed investigation thereof.
Incidentally, Propionibacterium acnes which settles in the sebaceous gland of the skin is an asporogenic anaerobic bacterium and it has been known as an exacerbation factor of acne vulgaris together with Staphylococcus aureus and Staphylococcus epidermidis in medium and serious cases of this disease. At the present time, there have been used a cream or a lotion containing an anti-microbial agent (such as erythromycin, tetracycline, nadifloxacin) in the treatment of the acne vulgaris, but the conversion of Staphylococcus spp. and P. acnes are converted into bacteria having resistance to these agents when using these agents over a long period of time and this becomes a clinical problem and accordingly, there has been discussed about measures against these resistant bacteria in the world-wide scale. There has not yet been reported any investigation of the effects of Sasa extracts on P. acnes. 
Prevotella bivia and Pigmented Prevotella spp. are present in the vaginae of the healthy females only in the cell count lower than the detection limit, but they are obligatory anaerobic gram-negative bacilli which can undergo abnormal proliferation under the conditions of bacterial vaginosis (BV) characterized by the reduction of cell count of lactic acid bacteria present in the vagina, the reduction of the pH value in the vagina and leucorrhea having a milk-like appearance and giving out a bad smell (an amine-like smell) and which accordingly belong to the category of bacterial vaginosis (BV)-related microorganisms, together with anaerobic gram-positive cocci including, for instance, Mycoplasma genitalium (hommnis), Gardnerella vaginalis and Peptostreptococcus anaerobius as representatives, as well as Porphyromonas spp. and they are quite important bacteria as the causative bacteria of infectious diseases in the uterus and basin.
It has been known that the Sasa extract shows an anti-microbial action, but there has not yet been conducted any investigation of the anti-microbial action of the Sasa extract on these bacterial species belonging to the BV-related bacterial group.
As has been discussed above, it has not been known whether the Sasa extract shows the anti-microbial activity effective for the entire bacteria and it has not generally been known whether the extracts derived from naturally-occurring substances having anti-microbial activities on bacteria likewise show anti-microbial activities even on the mold such as Candida. 
On the other hand, the tetanus is a toxin-induced disease showing a high lethality, in which a wound site is infected with Clostridium tetani and the neurotoxin produced at that site mainly causes muscle cramp, muscular rigidity and the accentuation of tendon reflex. The Clostridium tetani is an anaerobic bacillus detected in the soil, and feces of human beings and animals and it has been recognized that the tetanus can effectively be treated and/or prevented by the auto-immunization with toxoid or the passive immunization with an anti-venom serum. However, it has not yet been known that the Sasa extract has an anti-microbial activity against the Clostridium tetani. 
Moreover, the virus is a quite fine pathogen which cannot undergo auto-growth, but can undergo parasitic growth in animals, plants or microorganisms and viruses can be divided into animal viruses, plant viruses and microbial viruses. There have been developed a variety of anti-viral agents for treating and/or preventing viral diseases, but there has still been desired for the development of agents having efficient anti-viral activities and free of any side effect.
Further, it has been known that tannin included in various kinds of plants shows anti-microbial activity. For instance, it is also well-known that tannin derived from plants other than Sasa has an anti-microbial activity against MRSA (mesitylene-resistant Staphylococcus aureus), but a problem arises such that the tannin cannot be used as an anti-microbial agent because of its serious side effect.